I have to say this is one of the most fascinating threads I've seen.
I deal with a lot of publications in scholarly journals for a living and I
can say that, if you can find a few papers that Kodak has published, it
will most likely have others as references. Those will have others as
references, too. You can probably come up with most of them that way.
Zack
On Sat, Feb 9, 2019 at 2:35 PM `Richard Knoppow <dickburk@xxxxxxxxxxxxx>
wrote:
Some time in the past Kodak published a book on the Kodak
Laboratories history. I have a copy but its in storage somewhere.
I just moved a bunch of stored material and now have even less
idea of location than I did before. This book was published on
some anniversary of the labs. It pointed out that emulsion making
was highly secretive with only a couple of people being in on the
whole thing. The researchers at the labs were very frustrated
because the production department would make changes in formulas
and techniques which they refused to share with the labs. This
diminished as the complexity of the emulsions became greater. It
also said that Kodak began to rely more on patents than keeping
trade secrets when the changes in the process became more rapid.
Patents had a lifetime of seventeen years (now twenty I think)
while one could protect a trade secret forever, at least in
theory. I think the period of change was in the 1960s but my
memory is not that good. As Bob points out virtually every step
in making film was subject to an enormous amount of specialized
knowledge. For the most part Kodak was ahead of the pack. They
got beat out a couple of times in the very early days. It seems
to me that AGFA beat them to gold sensitizing which made a
substantial increase in film speed and AGFA also beat them to
devising a color film with contained couplers. Kodachrome used
separate couplers which were in the developing solutions
requiring a very complex devloping process. At the time
Kodachrome was released as a commercial product AGFA had
announced a contained coupler color film. It was not as good as
Kodachrome but much simpler to process and could be used as a
negative-positive process. Kodak eventually caught up but it took
a while.
It seems to me Kodak's whole existence was based on the idea
that the difficult part of photography lay in the making of the
sensitive material rather than processing it. They did the hard
part at the factory and also made processing simple enough to do
at home beside offering a developing service. This was only
partly true of Kodachrome because it had a very convoluted
processing procedure which needed great care and control but it
was almost unique in Kodak history.
Most may be aware of the long patent fight between Kodak and
Ansco over nitrate film support. This was the material that made
flexible film possible. I think Kodak lost this but have to read
the history again. Both nitrate and acetate film base have a
rather limited lifetime. The fairly recent attempts at restoring
old movies has shown that Kodak's film base was more stable than
either AGFA/Ansco or DuPont the two film manufacturers who were
Kodak's main competitors. While other manufacturers certainly
made good stuff Kodak was always ahead and had a reputation for
reliability and consistency that made it first choice for the
movie business.
Also, Mees said somewhere that the great number of developing
agents just proved how many ways there were of doing the same
thing. D-76 was probably the first developer to be the result of
any research and design. After it was announced it became the
standard developer for motion picture negative film. Every
manufacturer of film or photo chemicals had a version of D-76
and, for that matter, of other essential formulas such as print
developers, higher contrast developers, etc. The variations in
the formulas show why one can be a little sloppy in mixing and
still have a solution that works well.
I will also point out that the research in determining
emulsion characteristics was done mostly at Kodak labs.
A lot of this research was published, at least where it
would not interfere with keeping trade secrets. When the labs
were founded in 1912 the publication was discussed. It was
decided to publish technical papers in established,
peer-reviewed, journals rather than in a house journal. As a
result it may take some searching around to find papers. However,
this approach resulted in the immediate respect for the papers
from the Kodak Research Labs.
I will have to look for my copy of the book on the Labs
history because I think there was much more in it. This was a
paper back book in a format similar to Kodak's later data booklets.
BTW, I found that much of the technical (but not artistic)
advice I got from my mentors when I started out (at maybe twelve)
was wrong and got in the way of making decent pictures. I found
if I followed the instructions in the Kodak Reference Handbook I
got good negatives and prints. So much for the magic. Despite my
lack of formal training in chemistry I was extremely curious
about the photographic process and tried to learn as much as I
was capable of understanding about it.
The question that started this thread is the key to the whole
thing, namely how does the developer know which halide particles
to convert to silver? And of course, there are many "reducing"
agents which will convert all of the halide to metallic silver
regardless of whether its been exposed to light or not. Only
certain ones and only under certain conditions can the exposed
halides be converted to metallic silver without converting
everything. This selectivity makes the whole process possible.
I am so glad Bob Shanebrook is among us, its rare to have
someone with first hand knowledge available. He is a wonderful
resource.
On 2/9/2019 8:39 AM, Robert Shanebrook (Redacted sender
makingkodakfilm for DMARC) wrote:
Reverse-engineering films is difficult. In contrast,
mechanical devices can be examined and duplicated. Simple
chemicals like photo processing chemicals can be analyzed and
components identified. The quantities of the components are
usually substantial that lend themselves to measurement and
reverse engineering. Making the dry or liquid packaged
processing chemical consists of simply combining the
materials. pH and temperature adjustments may be
necessary but typically there are not complex chemical
reactions that don't go to completion.
Emulsion making is much more complex. The reactions that
create silver halide (AgX) crystals must be very carefully
controlled. This determines the shape and size of the crystals.
In addition the presence of materials in minute (parts per
million) quantities will determine the characteristics of the
grain. Seemingly tiny differences in emulsion making can make
significant differences in film performance. Even if the
components are know the processes used to create the results
can't be determined by reverse engineering. The manufacturing
process differences and the minute material differences are
nearly impossible to detect in examining film as it is sold.
Knowledge base is difficult to sustain. The knowledge was based
on a mentor-student and a team model. Briefly:
New films were designed by a team of about 15 primary members
each of which was supported by other teams of 100s of experts
and engineers. Primary team members typically had at least 15
years experience on various film assignments but were now
specialist in some aspect of emulsion making, coupler making,
systems analysis, coating, finishing etc. It was impractical for
any one to be adequately qualified in more than a one or two of
these fields. As a result the knowledge base is spread over
hundreds of people. There are records but they don't capture
all the judgement and complex reasoning that contributes to the
film design. Economics has forced the reduction in people.
As a result, today the knowledge base has to be less and
not replaceable.
The accomplishment of making EKTACHROME 100 Film in 2018 was
truly an extraordinary accomplishment. Those involved have my
respect.
Kodak paid attention to other film manufacturers. Technology
could be monitored through patents and examining the films.
Kodak patented T-grains so others could license the technology
or create them by working around the patent.
When new films were being developed the films of other
manufacturers were included in testing. The testing and
design that lead to PORTRA Film is described in "Making KODAK
Film".
Bob
www.makingKODAKfilm.com <http://www.makingKODAKfilm.com>
On Saturday, February 9, 2019, 8:17:47 AM EST, Myron Gochnauer
<goch@xxxxxx> wrote:
On Friday, February 8, 2019, 7:38:12 PM EST, Robert Shanebrook...
<dmarc-noreply@xxxxxxxxxxxxx
<mailto:dmarc-noreply@xxxxxxxxxxxxx>> wrote:
In September 2003 Kodak announced they would not longer be
investing in the improvement of camera films. I retired in
October 2003.
The films introduced since 2003 were small refinements on the...
existing films that were previously under development or
resuming a former film.
Sadly, Kodak's institutional knowledge is reduced to very
few people. I don't think they have the resources to make
improvements. However, I am not aware of any serious
shortcomings in their ability to make emulsions or coat film.
They are extending the life of existing film products.
Good Grief!! As a ‘civilian’ in these matters, I have always
assumed that the primary problem for the future of film was the
aging of highly sensitive production equipment that was too
costly to replace given the reduced market. I thought that the
/knowledge/ base was readily available.
Here’s a related question: If a small team of scientists and
engineers had access to, say, Tri-X Pro (current version), D76,
the user instructions Kodak provides, and a basic understanding
of the end purpose of film, do you think that they could reverse
engineer the film?
And suggested by that question: To what extent did film
manufacturers “look under the hood” of their competitors
products? (For example, what did Ilford know about Kodak’s
T-grain once it was out in the late 80’s?)
Myron
--
Richard Knoppow
dickburk@xxxxxxxxxxxxx
WB6KBL
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